Notebook[List[Cell[BoxData[FormBox[RowBox[List[RowBox[List[SubscriptBox["S", "k"], "=", RowBox[List["(", GridBox[List[List[RowBox[List["cos", "(", RowBox[List[SubscriptBox["\[Omega]", "k"], "*", "time_stamp"]], ")"]], RowBox[List["-", RowBox[List["sin", "(", RowBox[List[SubscriptBox["\[Omega]", "k"], "*", "time_stamp"]], ")"]]]]], List[RowBox[List["sin", "(", RowBox[List[SubscriptBox["\[Omega]", "k"], "*", "time_stamp"]], ")"]], RowBox[List["cos", "(", RowBox[List[SubscriptBox["\[Omega]", "k"], "*", "time_stamp"]], ")"]]]]], ")"]]]], ","]], TraditionalForm]], "Input"]]]